DES MOINES, Iowa - Republican presidential hopeful Michele Bachmann is telling college students in politically important Iowa that all Americans should pay taxes since they all benefit from services such as roads and bridges, national defense and the courts. Her position, which she was outlining today at Iowa State University in Ames, is a direct challenge to rivals Rick Perry and Herman Cain, who are advocating plans that would allow low-wage earners to continue paying no taxes while implementing a form of a flat tax on all other workers. The Tax Policy Center estimates that some 46 percent of households...